coli C ΔnagA ΔagaR. This demonstrates

that constitutive synthesis of AgaA can substitute for NagA in a ΔnagA mutant and allow it to grow on GlcNAc (Figure 3) just as NagA can substitute CYT387 cell line for AgaA in a ΔagaA mutant (Figure 2 and Table 1). It is interesting to note that unlike in glycerol grown E. coli C ΔnagA where nagB was induced 19-fold (Table 1), in glycerol grown E. coli C ΔnagA ΔagaR, where agaA was constitutively expressed, the relative expression of nagB was down to 2-fold (Table 2) which is the same as that in Aga grown E. coli C ΔnagA (Table 1). Thus, either the induced expression of agaA in E. coli C ΔnagA by growth on Aga (Table 1) or the constitutive expression of agaA in glycerol grown E. coli C ΔnagA ΔagaR (Table 2), turns down nagB induction significantly. Both these experiments Saracatinib ic50 indicate that

AgaA can deacetylate GlcNAc-6-P. Figure 3 Growth of E. coli C and mutants derived from it on GlcNAc. E. coli C and the indicated mutants derived from it were streaked out on GlcNAc MOPS minimal agar plates and incubated at 37°C for 48 h. Table 2 Analysis of gene expression in E. coli C, ∆agaR , and ∆nagA ∆agaR mutants by qRT-PCR Carbon Sourcea Strain Relative expression of genes in E. coli C     agaA agaS nagA nagB agaR Glycerol E. coli C 1 1 1 1 1 Aga E. coli C 32 62 1 1 2 GlcNAc E. coli C 3 3 16 23 2 Glycerol E. coli C ∆agaR 50 175 1 1 NDb Aga E. coli C ∆agaR 57 177 1 1 ND GlcNAc E. coli C ∆agaR 20 92 6 13 ND Glycerol E. coli C ∆nagA∆agaR Selleck PRN1371 54 197 ND 2 ND Aga E. coli C ∆nagA∆agaR 74 224 ND 3 ND GlcNAc E. coli C ∆nagA∆agaR 47 148 ND 26 ND a Carbon source used for growth. b ND indicates not detected. Complementation studies reveal that agaA and nagA can function in both the Aga and the GlcNAc pathways The genetic and

the qRT-PCR data Etofibrate described above show that agaA and nagA can substitute for each other. The relative expression levels in Table 1 show that in Aga grown ΔagaA mutants, nagA and nagB and thereby the nag regulon were induced and in E. coli C ΔnagA ΔagaR, agaA and agaS and thereby the whole aga/gam regulon were constitutively expressed. Although both regulons were turned on it is apparent that the expression of nagA in ΔagaA mutants and the expression of agaA in E. coli C nagA ΔagaR allowed growth on Aga and GlcNAc, respectively, and not the other genes of their respective regulons. In order to demonstrate that this is indeed so and to provide additional evidence that agaA and nagA can substitute for each other, we examined if both agaA and nagA would complement ΔnagA mutants to grow on GlcNAc and ΔagaA ΔnagA mutants to grow on Aga and GlcNAc. EDL933/pJF118HE and EDL933 ΔagaA/pJF118HE grew on Aga and GlcNAc, EDL933 ΔnagA/pJF118HE grew on Aga but not on GlcNAc, and EDL933 ΔagaA ΔnagA/pJF118HE did not grow on Aga and GlcNAc (Figures 4A and 4B).